The invention relates to guide or feed rollers for paper and foil handling apparatus, for example, for printing presses.
In machines of the above type, guide and feed rollers are utilized to align sheets of paper or plastic foil so as to direct them and to feed them evenly through the machines. The rollers have to be well balanced, they must be resistant to bending and also resistant to corrosion and should have a low mass. Their surface should further provide traction so as minimize slipping between the rollers and the sheets.
Metallic rollers as presently in use are not capable of fulfilling all these requirements. Metal rollers with high bending resistance and good balance, for example, usually have large masses and they also have a smooth non-gripping surface. In many cases the minimum wall thickness required for the necessary bending resistance cannot be obtained in an economical manner because of manufacturing problems so that the weight of the rollers is larger than necessary.
It is the principal object of the present invention to provide guide or feed rollers with a surface adapted to engage the surfaces of the paper or foil sheets so that they require only a small looping angle for sufficient traction as feed rollers and which are not susceptible to imbalance and furthermore, have a high bending resistance, small mass and permit high feed speeds.